Two bombs exploded at the finish line of Monday's Boston Marathon, killing three people. A Massachusetts Institute of Technology police officer was killed during Thursday night's manhunt. More than 180 people were injured in the explosions.

Twenty-six-year-old suspect Tamerlan Tsarnaev was killed Friday. His brother, 19-year-old Dzhokhar Tsarnaev, was captured later Friday inside a boat parked in a Watertown backyard after a furious search. He is recovering at a Boston hospital guarded by armed officers.

The governor declined to comment on the investigation.

Dzhokhar Tsarnaev capture ends historic manhunt

On Saturday's "CBS This Morning," correspondent John Miller described Friday's capture of Dzhokhar. Based on "the amount of blood" the homeowner saw in the boat, it is likely Dzhokhar was shot as long as 20 hours before being discovered, Miller said, referring to the battle earlier Thursday that led to the death of Tamerlan.

It was a "fierce gun battle with police after the carjacking and the car chase, at which point they were apparently exchanging gun fire, but also throwing homemade grenades and one large satchel bomb at police officers, so he had been bleeding for a long time," Miller said.

In a photo of authorities apprehending Dzhokhar released Friday, a SWAT team medic can be seen administering an "ambu" resuscitation bag to assist him in his breathing. Another photo shows Dzhokhar climbing out of the boat under his own power, following the commands of the HRT (Hostage Rescue Team), and Miller said it is clear from the images that, "this is a guy who was very weak at this point and probably -- had he not been discovered -- he might not have lived."